I think i can help...
First: Your role in PVP/RVR as a 2 handed Offtank is to deal dmg to light amored classes, mainly healers and brightwizards. Second job is to protect your healer.
I'm a lvl 40 Chosen, playing in a daily static group, so listen:
We, our 5 lvl 40 Chosens, that skilling dual in the first and the third tree is the best. But why?
Your need just 1 talent from the first tree: 15% more Crit!
From the third tree you need earthquake, which is nearly our best skill. The Rest of your points you have to put also in the third tree to push Ravage, which is your main attacking skill.
As aura you use the resistance aura to reduce your enemys resistance and to protect your self.
Use the moloch tactic to get better out of snares, what is really important.
The second one is the tactic, which reduces the timer of your "Dmg-over-runtime"-skill (touch of ***). With this tactic you can hold the touch on your enemy the whole time.
Third is +toughness. for more protection.
the fourth is the 15% crit we skilled.
You need on lvl 40 only about 400 strength. With this strength your ravage crits on normal resistance with light amor for about 600.
Max your Wounds and Toughness. you will need about 600 Toughness and min. 8k life to be a good offtank and to rock pvp.
How to work with this?
Start your resistance aura, take your aim, knock everyone down with earthquake, spot on your enemy target, spam touch and then ravage him till the death.
I'm german so i hope you understand what i tried to tell you.
ps. I hated my Chosen when i was 32... but with 40 the world is a whole different. Keep on going.
My stats now:
240 weapon skill
Resis: 730, 822, 650